Last post Mon, Jun 16 2008 6:55 PM by ArkanzanWheeler. 36 replies.
ArkanzanWheeler: There are many manufacturers of custom frames that make rigid trike frames. As for just adding another wheel out to the side, I suppose that confuses me a bit. Maybe you could just build an outrigger setup. Sort of like a sidecar without the car. I tried the sidecar route for a bit. Was very dangerous for my riding style.
I believe that in trying to use some of your old car parts to make a rearend you will likely find yourself trying to reinvent the wheel. Several considerations come to mind. Weight, sprocket fitment to spider gears, bearings, brakes to name a few and those take no consideration regarding the housings for your differential and sprocket nor the axle tubes and such.
In answer to your question about my setup, the rearend wheels and all was 44" wide. To get a good feel of exactly how it would feel do this. Extend both arms out at 90 degrees. Now drop them both to about 45 degrees. At that position you could curl your fingers over the outside edge of the tires on each side. As for how it handles, I illustrated that to the best of my ability in my first or second post.
The wheels you see on the 3rd gen trike are the exact width of the ones on the first. They are lower profile on the 3rd gen. for 2 reasons. 1.) In setting this one up I wanted to match as closely as possible the the same RPM range as a stock HD. The only way to do that was to calculate the rpms of the stock tires used on factory bikes at 60 mph. in their final drive. Having that information I knew what the rpms of the motor should be also. I then went about the task of matching my own to approx the same. A chore in that the servi-car sprocket is only 37 teeth as opposed to the 51 tooth sprocket of a stock big twin. The lower profile tires gave me a lot more leeway in my already limited choice of front sprockets. 2.) Another very important choice for not only the ultralight weight wheels but the tires as well is weight. Unsprung wheel weight to be even more precise. The less weight that is unsprung, the less recoil it has when hitting bumps in the road etc. The large tires like you saw on the original bike had me all over the road sometimes. Not only that they always felt spongy. Where the lighter low pro tires were firm and had virtually no spongy feel to them. Same as it would have on your favorite sports car. And when they hit a bump, they came back down with a firm thump and were instantly back in action. The large tires would bounce 2 to 3 times a little before finally resting again at a normal ride. There is one other advantage also, the acceleration factor from dead stop. Again, when riding with other bikes, all Harleys as well, it really turned some heads to see this trike, with its obvious added weight of the rearend, along with my present girlfriend and all my luggage pull away from them from start to top speed. I got used to being called a liar about what the engine had in it.
You ask did it have positive traction. I resound with an unequivocal NO! Do NOT consider live axles for ANY 3 wheeler unless you have a death wish. Live with the fact that the wheel with the least amount of traction is the one that is going to get all the power. That may seem annoying to some, but in this case it is an absolute blessing!
tsh3406: Thank you so much for posting the link to trikeenvy.com. They have on there a trike rearend that can be purchased (if the site is not a mistake) that is the absolute most reasonable price I have ever seen or heard of! Anyone interested can look at it here. It is trike rearend #3. Unheard of price. I am sure that must be euro or some sort of mistake. Worth a call though if you are serious.
TotalMechanic: Found the link for the IRS rearend you asked about. It is http://www.jbp-trikes.com/home.html. Here is another as well.
W0lf,
So far I have decided that my physique pretty much dictates that I pursue a sportbike powered reverse trike with a funny car style tub, because of the following reasons:
Due to frozen hip sockets from arthritis the width between my legs when measured between the knees is fixed at no more and no less than 6". As well I am bent over forward at the hips at a 20-30 deg angle. (I don't use any devices to walk. I just use /abuse my knees and ankles to shuffle!) Additionally, as the muscles on my backside and upper thighs are atrophied I have no padding back there. (Tailbone sticks way out.) It may be hard to picture but the end result is that I cannot straddle a conventional motorcycle or even the conventional trike conversions that exist. The bottom line is this: If the motor sits under me so that it has to be straddled I cannot use it.
I like the regular flavor trike for it's simplicity and especially the low slung IRS with rear diff designs you posted but from what I see they too require a straddling posture.
The other design idea that I flirted briefly with was a modified two-wheel sportbike with the seat, back fairings and supports cut away and a wedge shaped fender covering the rear wheel and chain. The riding posture would be prone: My chest would be lying on top of the fuel tank bulge and my legs sitting parallel to the ground. If you saw the movie, "The World's Fastest Indian" about Burt Munro, that would be what I had in mind. The link below shows the pictures of the original bike and the modified Ducati that were used in the movie.
http://www.indianmotorbikes.com/features/munro/munro.htm
Munro used two small retractable outrigger casters to stabilize the bike when it was at a standstill and while running at low speed. The major downside of this design is stability in high-speed maneuvering, ability of the rider to see over the handlebars and a need to wear a medieval suit of armor in the event the bike tipped! Definite safety issues. One idea that now occurs to me after your posts is this: Combine the prone posture with a bike with two rear tires on a Tiltster/IRS/Rear Diff setup. It would solve the stability and safety issues, the only issues/compromises as I see it would be riding comfort and visibility issues for the rider. I won't really know what it would be like to ride such a beast until I actually had to do it! I will have to ponder this idea some more as the concept now has me intrigued.
Arkansan,
This is close to the same as what was on the tail of the Ninja:
Here is the one I made for my car:
The L67 is easy to put in a GT, but it is best to get the GTP Heavy Duty Transmission also. You will also need the PCM from a GTP.
